In this post, we have tried to compile most of the frequently and commonly used reagents in our Forensic Chemistry Laboratories. So, it is important to have the basic information on how to make these reagents and their usage to detect or distinguish the drugs in question.
Let us take a look at the commonly used Reagents in Forensic Chemistry Laboratory in this table.
| Reagents | Preparation of Reagent | Used for |
| Chen- Kao Reagent | Reagent 1: This is prepared by adding 1 ml of Glacial Acetic Acid in 100 ml of Water, i.e., 1% (V/V) aqueous Acetic Acid solution. Reagent 2: This is prepared by dissolving 1 gm of Copper (II) Sulphate in 100 ml of Water, i.e., 1% (W/V) aqueous CuSO4 solution. Reagent 3: This is prepared by dissolving 8 gm of Sodium Hydroxide in 100 ml of Water, i.e., 2N aqueous Sodium Hydroxide solution | Distinguish ephedrine, pseudoephedrine, norephedrine, and methcathinone from amphetamine and methamphetamine |
| Chromotropic acid reagent | Dissolve 1 g of chromotropic acid disodium salt in water, add 20 ml of 2% ascorbic acid solution, and dilute with water to 100 ml. | Compounds having formaldehyde |
| Cobalt Thiocyanate( Ruybal test) | Dissolve 2.0 g of cobalt (II) thiocyanate in 100 mL of distilled water. | Cocaine , Heroin Ephedrine, Meperidine, Phencyclidine, Procaine, Propoxyphene and Pseudoephedrine methadone,etc. |
| Dille-Koppanyi Reagent | Solution A: Dissolve 0.1 g of cobalt (II) acetate dihydrate in 100 mL of methanol. Add 0.2 mL of glacial acetic acid and mix. Solution B: Add 5 mL of isopropylamine to 95 mL of methanol. | Barbiturates |
| Dragendorff reagent | 1 gm of Bismuth SubNitrate is dissolved in 3 ml. of 10M of Hydrochloric Acid. It is diluted to 20 ml. 1 gm of Potassium iodide is dissolved in it | Primary or Secondary or tertiary amine Alkaloids & benzodiazepines Amphetamine Active constituents of Papaver somniferum |
| Duquenois-Levine Reagent | Solution A: Add 2.5 mL of acetaldehyde and 2.0 g of vanillin to 100 mL of 95 percent ethanol. Solution B: Concentrated hydrochloric acid. Solution C: Chloroform. | Cannabis |
| Ferric Chloride Reagent | Dissolve 2.0 g of anhydrous ferric chloride or 3.3 g of ferric chloride hexahydrate in 100 mL of distilled water. | Compounds containing Phenols, Phenothiazines, Salicylates, |
| Fisher Morris Reagent | Reagent A: Concentrated Formic Acid. Reagent B: 5% aqueous Sodium Nitrite solution. | Heroin, Diphene, hydramine, Diazepam |
| Forrest Reagent | 0.2% solution of Potassium Dichromate, 30% (v/v) solution of Sulphuric Acid, and 20% solution of Perchloric Acid and a 50% solution of Nitric Acid in equal volumes are mixed. | Phenothiazines Imipramine and related compounds |
| FPN Reagent | 5 ml. of Ferric Chloride solution, 45 ml. of 20% (w/v) solution of Perchloric Acid and 50 ml. of 50% (v/v) solution of Nitric Acid is added to make a final solution | Phenothiazines |
| Frohde’s Reagent | Dissolve 0.5 g of molybdic acid or sodium molybate in 100 ml of hot concentrated sulfuric acid | MDA (amphetamine) Oxycodone |
| Mandelin Reagent | Dissolve 1.0 g of ammonium vanadate in 100 mL of concentrated sulfuric acid. | amphetamines and opiates Ergot Alkaloids. |
| Marquis Reagent | Carefully add 100 ml of concentrated sulfuric acid to 5 ml of 40 percent formaldehyde | Primary test for opiates, hallucinogens, and amphetamines |
| Mayer’s Reagent | Potassium Mercury Iodide prepared by dissolving 1.357 gm of Mercuric Chloride and 5 gms of Potassium Iodide in 100 ml of water | Nicotine |
| Mecke Reagent | Dissolve 1 g of selenious acid in 100 ml of concentrated sulfuric acid. | MDA, Mescaline |
| Para-Dimethylaminobenzaldehyde (p-DMAB)Reagent | Add 2.0 g of p-DMAB to 50 mL of 95 percent ethanol and 50 mL of concentrated hydrochloric acid. | LSD |
| Scott Reagent | 2 gms of Cobalt Thiocyanate in water and diluted with 96% Glycerine in water in 1:1 proportion. | Cocaine |
| Simon’s Reagent | Solution A: Dissolve 1 g of sodium nitroprusside in 50 mL of distilled water and add 2 mL of acetaldehyde to the solution with thorough mixing. Solution B: 2 percent sodium carbonate in distilled water | Methamphetamines |
| Van- Urk Reagent OR Ehrlich’s reagent | 1 gm. of p-amino benzaldehyde is dissolved in 100 ml. ethanol and adding 10 ml. of Hydrochloric Acid. | Lysergic Acid Diethylamide |
| Zwikker Reagent | Solution A: Dissolve 0.5 g of copper (II) sulfate pentahydrate in 100 mL of distilled water. Solution B: Add 5 mL of pyridine to 95 mL of chloroform | Barbiturates |
Hope we have incorporated all the Commonly used Reagents in Forensic Chemistry Laboratory. If we have missed out on something, please let us know in the comment section. Happy Reading 🙂
What a wonderful post.. thank you for sharing it
What a wonderful post. Things of reagents mostly used in labs compiled at one place. so cool!!